Weltrichia

Weltrichia is a genus belonging to the extinct seed plant group Bennettitales. It is a form genus representing flower-like male pollen-producing organs. It is associated with the female ovulate cone ''Williamsonia.''

Description

Although the morphology of Weltrichia is highly variable, the overall morphology consists of a central cup-like structure surrounded by a number of radially symmetrical outward projecting rays, to which are attached bivalve-shaped pollen sacs/synangia. The number of rays varies from 9/10 to 30, depending on the species, and the total diameter from to over. Both the cup and rays usually have substantial thickness, in some of the thicker species the structure is noticeably woody. The pollen is monocolpate and elliptical. In some species, additional rays project over the central cup, and attractants/resinous substances are present within the cup. The rays also sometimes have ridges, trichomes, appendages, striae and/or unipinnate pollen sacs present. Species of Weltrichia appear to have primarily been wind pollinated, though some species may have been pollinated by insects, such as beetles. They were borne by the same plants that also bore female ovulate cones assigned to Williamsonia. It is unclear whether the parent plants were monoecious or dioecious. At least some bearers of Weltrichia, such as Kimuriella from the Late Jurassic of Japan were low growing divaricately branching shrubs with a maximum height of 2–3 metres, while others such as Williamsonia gigas may have been more cycad-like in morphology.

Distribution

Weltrichia is known from Asia, Europe, and North America, as well as India, spanning from the Late Triassic to the Late Jurassic/Early Cretaceous.

Species

After Popa and subsequent literature.

Species	Location	Age	Notes	Image
Weltrichia alfredii	Romania	Early Jurassic	About 120 mm in diameter
Weltrichia alpina	Germany	Late Triassic	About 54 mm in diameter
Weltrichia antonii	Romania	Early Jurassic	About 100 mm in diameter, with only 9/10 rays, has the lowest number of rays of any species
Weltrichia ayuquiliana	Mexico	Middle Jurassic	Around 60 mm in diameter
Weltrichia daohugouensis	China	Middle Jurassic	Around 100 mm in diameter
Weltrichia fabrei	France	Late Triassic-Early Jurassic	Only known from fragmentary remains
Weltrichia givulescui	Romania	Early Jurassic	Maximum of 100 mm in diameter
Weltrichia harrisiana	India	Middle Jurassic	Approximately 120–150 mm in diameter
Weltrichia hirsuta	Iran	Early Jurassic	Approximately 130–140 mm in diameter
Weltrichia huangbanjingouensis	China	Late Jurassic/Early Cretaceous	Only central cup is preserved
Weltrichia johannae	Romania	Early Jurassic	70 mm in diameter
Weltrichia maldaensis	India	Late Jurassic	70 mm in diameter
Weltrichia microdigitata	Mexico	Middle Jurassic	Diameter of only 30 mm, making it smallest known species
Weltrichia mirabilis	Germany	Early Jurassic	Approximately 100 mm in diameter
Weltrichia mixtequensis	Mexico	Middle Jurassic	Diameter of 160 mm
Weltrichia oolithica	Italy	Late Jurassic	70–80 mm in diameter, holotype specimen currently unlocated
Weltrichia pecten	England	Middle Jurassic	Typically 100–120 mm in diameter. Has been suggested to be synonymous with Weltrichia spectabilis and Weltrichia whitbiensis.'
Weltrichia primaeva	Iran	Early Jurassic	Only known from large ray fragments with a complex morphology
Weltrichia santalensis	India	Middle-Late Jurassic	With a diameter of 220–230 mm, it is one of the largest species in the genus
Weltrichia setosa	England	Middle Jurassic	Typically 120 mm in diameter.
Weltrichia sol	England	Middle Jurassic	One of the largest species, at 170–200 mm in diameter, associated with the female cone Williamsonia gigas and the leaves Zamites gigas
Weltrichia spectabilis	England	Middle Jurassic	Central cup 40 mm in diameter and rays 30-50 mm in length, which bear apical filiform whiskers, which can reach 30-60 mm in length. Has been suggested to be synonymous with Weltrichia pecten and Weltrichia whitbiensis.'
Weltrichia steierdorfensis	Romania	Early Jurassic	Around 105–120 mm in diameter
Weltrichia whitbiensis	England	Middle Jurassic	Around 120–130 mm in diameter. Has been suggested to be synonymous with Weltrichia pecten and Weltrichia spectabilis.''''
Weltrichia magna	Mexico	Middle Jurassic	Around 226 mm in diameter.
Weltrichia xochitetlii	Mexico	Middle Jurassic	Approximately 30–45 mm in diameter